This invention relates to a memory address system and more particularly to a memory address and control system for providing memory address for measured video signals from a television camera undergoing automatic setup when viewing a test chart.
In systems for automatically adjusting the geometry or video levels of the three color channels of a highquality color TV camera, it is necessary to measure the parameters to be adjusted, and store the data for calculation of errors and required corrections. Such measuring techniques and discussed in U.S. Pat. No. 4,133,003 of Flory and Oakley and U.S. Pat. No. 4,141,040 of Dischert and Flory. Also for a discussion of the automatic system see "AUTOMATIC SETUP SYSTEM FOR TELEVISION CAMERAS," of Brian Astle and Robert Dischert, International Application filed under the Patent Cooperation Treaty, Ser. No. PCT/US79/00099, filed Feb. 22, 1979 and "AUTOMATIC SETUP SYSTEM FOR TELEVISION CAMERAS," of Robert Dischert, U.S. Application Ser. No. 894,008, filed Apr. 6, 1978.
Current technology usually specifies digital data storage, and therefore digital words must be generated for the addresses in memory where each data word will be stored.
In the camera system cited above the main spatial and video level functions are measured in nine locations on the raster. An array of (objects or blocks) features on a test chart comprise the test pattern used when measurements are made. It is possible to measure all spatial or level errors in one field, so it is necessary to generate addresses for all video locations in real time, to allow a single set of measurement hardware to measure at all locations, each in turn, with time to transfer data to memory and reset measuring system--all before the next location is reached.
If video is used to generate addresses for data storage, it is essential that addresses correspond only to valid video. Any stray specks of dirt or other camera tube or test chart flaws can cause false addressing. Since the scanning of the test chart by the standard TV scan proceeds in an orderly fashion side-to-side and top-to-bottom, it should be possible to address the memory by counting video pulses in order of the scan in a digital counter. In fact, if the chart is rotated with respect to the camera pickup tube, this order cannot be assured.